Oscar stoddard



(No Model.)

0. STODDARD. KEY HOLE GUARD.

No. 423,349. Patented Mar. 11, 1890,.

. specification.

being old.

UNITED STATES PATENT OFFICE. y

OSCAR STODDARD, OF DETROIT, MICHIGAN, ASSIGNOROF TlVO-THIRDS TO ANSON D. BESIMER AND JAMES S. DEXVEY, OF SAME PLACE.

KEY-HOLE GUARD.

SPECIFICATION forming part of Letters Patent No. 423,349, dated March 11, 1890.

Application filed September 14:, 1889. Serial No. 323,967.v (No model.)

To all whom it may concern.-

Be it known that I, OSCAR STODDARD, a citizen of the United States, residing at De troit, in the county of WVayne and State of Michigan, have invented certain new and useful Improvements in Key-Hole Guards for Locks; and I do declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same, reference being had to the accompa nyin g drawings, and to the letters of reference marked thereon, which form a part of this This invention relates to lock-case attachments, and particularly to key-hole guards; and it consists of double steel plates adapted to slide transversely on parallel supports within the lock-ca so as the key is inserted in the lock, thus closing the opening of the keyhole in the opposite side of the lock-case.

The object of the invention is to provide a covering or guard for the key-hole, so as to prevent the manipulation of the key or works of the look by the insertion of a tool or in strument into the look through the key-hole when the door is locked and the key left in the lock, all of which will be fully hereinafter set forth, and the essential features of the device pointed out particularly in the claim.

In the accompanying drawings, forming a part of this specification, Figure l is a view of a lock-case, the back plate being removed, showing the guard-plates located therein. Figs. 2, 3,"and a are details to be referred to. Fig. 5 is a view in elevation of the sliding guard-plates detached from the lock. Fig. 6 is a view of the key, the end being broken away, showing chamber therein.

As indicated in the drawings, A represents the key; B B, the sliding guard-plates; D and E, the lock-case, and h the key-hole therein.

The frame D of the lock-case at the side of the key-hole thereof is provided with the laterally-extending pin (L. The flange D of said case 011 the opposite side of the key-hole is provided with projecting rib a, said pin and rib extending entirely across the space between the outer plates of the lock-case, as shown in Figs. 1, 3, and 4, all of said parts The guard-plates B are made of springsteel formed slightly concavo-convex, having in their end portions the hole 0 and notch e,- respectively. Said plates are placed with-their concaved faces together, the bearing being at the ends of the plates, as shown in Figs. 1 and 2. The holes 0 and notches e in the end of said plates register with each other. Said holes 0 freely receive the pin a, and the 'notchcs e fit loosely on the rib or bead ct.

(See Fig. 1.) Said pin and rib form the supports on which the guard-plates slide back and forth between the plates D and E of the lock-case by the action of the key. The. guard-plates B are also provided on their outer or convexed face with the studs Z. Said stud enters the chamber 0 in the end of the key when the key is inserted in the lock and forms the support on which the inner end of the key rotates in operating the bolt of the look; but when locking and unlocking the door, as the wing of the key is turned, the plates will spring together, allowing the key to be freely turned, as shown by dotted lines 7 5 in Fig. 3, and operate the bolt of the lock. The pin a and rib or bead a should be located at such distance from each other as will allow the key to rotate or turn around between them, and the sliding guard-plates should be sufficiently large to completely cover the key-hole in the case, as clearly shown in Fig. l, in which the dotted lines indicate the keyhole covered by said plates.

The operation is as follows: The parts be ing arranged as shown and described, and the key being inserted in the look from the left, (see Fig. 2,) the plates B will be forced l against the inner face of the opposite part D of the lock-case, covering the key-hole in said part and holding the plates securely over said key-hole while the key is turned in the lock. The stud Z, projecting into the key-hole, serves to guide the key when inserting it from the opposite side. The plates B B 5 straighten as the key is forced into the lock, and by their pressure said key is held in any position within the lock-case at one side of the key-hole, and when the key is turned so as to register with the key-hole said plates IOC expel it from the lock. As the key is illserted from the right, (see Fig. 3,) the plates will slide back, covering the key-hole in the opposite side of the lock-case, as before described.

The view of Fig. 4 is a section on dotted line of Fig. 1, showing the studs Z Z of the spring-plates as they register with the keyholes h h in the lock-case.

From the drawings and foregoing description it will be apparent that when the door is locked from the outside and the key left turned in the lock the guard-plates will be firmly held against the outer key-hole opening, completely closing said opening and rendering impossible access to the key or works of the look from the outside through the keyhole.

Having thus fully set forth my invention, what I claim as new, and desire to secure by Letters Patent, is

In combination with a lock-case and its key-hole, horizontal supports crossing said lock-case internally and a set of curved springmetal plates loosely mounted on the crossing supports and having on their outer faces a stem adapted to receive the end of a key, said spring-plates adapted to be moved from side to side of the lock by the insertion of the key and to hold the key when turned Within the look at one side of the key-hole, as and for the purposes specified.

In testimony whereof I affix my signature in presence of two witnesses.

' I OSCAR STODDARD.

Witnesses:

' E. S. WHEELER,

R. B. WHEELER. 

